PyQt5快速开发与实战 8.6 设置样式

PyQt5快速开发与实战

8. 第8章 PyQt5 图形和特效

8.6 设置样式

8.6.1 为标签添加背景图片

from PyQt5.QtWidgets import QApplication, QLabel, QWidget, QVBoxLayout, QPushButton
import sys


class WindowDemo(QWidget):
    def __init__(self):
        super().__init__()

        label1 = QLabel(self)
        label1.setToolTip('这是一个文本标签')
        label1.setStyleSheet("QLabel{border-image: url(./images/python.jpg);}")
        label1.setFixedWidth(476)
        label1.setFixedHeight(259)

        vbox = QVBoxLayout()
        vbox.addWidget(label1)
        vbox.addStretch()

        self.setLayout(vbox)
        self.setWindowTitle("Label添加背景图片例子")


if __name__ == "__main__":
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = WindowDemo()
    win.show()
    sys.exit(app.exec_())

8.6.2 为按钮添加背景图片

from PyQt5.QtWidgets import QApplication, QLabel, QWidget, QVBoxLayout, QPushButton
import sys


class WindowDemo(QWidget):
    def __init__(self):
        super().__init__()

        btn1 = QPushButton(self)
        btn1.setObjectName('btn1')
        btn1.setMaximumSize(64, 64)
        btn1.setMinimumSize(64, 64)
        style = ''' #btn1{ border-radius: 30px; background-image: url('./images/left.png'); } #btn1:hover{ border-radius: 30px; background-image: url('./images/leftHover.png'); } #btn1:Pressed{ border-radius: 30px; background-image: url('./images/leftPressed.png'); } '''
        btn1.setStyleSheet(style)


        vbox = QVBoxLayout()
        vbox.addStretch()
        vbox.addWidget(btn1)

        self.setLayout(vbox)
        self.setWindowTitle("按钮添加背景图片例子")


if __name__ == "__main__":
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = WindowDemo()
    win.show()
    sys.exit(app.exec_())

8.6.3 缩放图片

from PyQt5.QtWidgets import QApplication, QLabel, QWidget, QVBoxLayout
from PyQt5.QtGui import QImage, QPixmap
from PyQt5.QtCore import Qt
import sys


class WindowDemo(QWidget):
    def __init__(self):
        super().__init__()
        filename = r".\images\Cloudy_72px.png"
        img = QImage(filename)

        label1 = QLabel(self)
        label1.setFixedWidth(120)
        label1.setFixedHeight(120)

        result = img.scaled(label1.width(), label1.height(), Qt.IgnoreAspectRatio, Qt.SmoothTransformation);
        label1.setPixmap(QPixmap.fromImage(result))

        # 3
        vbox = QVBoxLayout()
        vbox.addWidget(label1)

        self.setLayout(vbox)
        self.setWindowTitle("图片大小缩放例子")


if __name__ == "__main__":
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = WindowDemo()
    win.show()
    sys.exit(app.exec_())

8.6.4 设置窗口透明

from PyQt5.QtWidgets import QApplication, QMainWindow
import sys

if __name__ == "__main__":
    app = QApplication(sys.argv)
    win = QMainWindow()
    win.setWindowTitle("窗口的透明度设置")
    win.setWindowOpacity(0.5)

    win.resize(350, 250)
    win.show()
    sys.exit(app.exec_())

8.6.5 加载QSS

在Qt中经常需要使用样式，为了降低耦合性(与逻辑代码分离)，通常会定义一个QSS文件，然后编写各种控件（如 QLable、QLineEdit、QPushButton)的样式，最后使用QApplication或 QMainWindow来加载样式，这样就可以让整个应用程序共享同一种样式了。

1. 编写QSS

   MainWindow{
       border: 1px solid rgb(45 ,45 ,45);
   }
   
   QToolTip{
       border: 1px solid rgb(45 ,45 ,45);
       background: white;
       color: red;
   }
   

2. 加载QSS

   编写一个加载样式的公共类CommonHelper

   class CommonHelper :
       def __init__(self ) :
           pass
            
       @staticmethod    
       def readQss( style):
           with open( style , 'r') as f:
              return f.read()
   

3. 主函数中加载

   import sys
   from PyQt5.QtWidgets import QMainWindow, QApplication, QVBoxLayout, QPushButton
   from CommonHelper import CommonHelper
   
   
   class MainWindow(QMainWindow):
       def __init__(self, parent=None):
           super(MainWindow, self).__init__(parent)
           self.resize(477, 258)
           self.setWindowTitle("加载QSS文件")
           btn1 = QPushButton(self)
           btn1.setText('添加')
           btn1.setToolTip('测试提示')
           vbox = QVBoxLayout()
           vbox.addWidget(btn1)
   
           self.setLayout(vbox)
   
   
   if __name__ == "__main__":
       app = QApplication(sys.argv)
       win = MainWindow()
   
       styleFile = './style.qss'
       qssStyle = CommonHelper.readQss(styleFile)
       win.setStyleSheet(qssStyle)
       win.show()
       sys.exit(app.exec_())